An RCDA is requested to support a comprehensive research program examining effects of chronic childhood illness on the social and behavioral development of children, siblings, and parents. Childhood illness is conceptualized as a major perturbation of the family system, providing an opportunity to study how families resolve ongoing problems, how developmental transitions are affected by chronic stress, and how families reorganize roles and relationships given greater demands on time and energy. Four major studies will be conducted: 1) development of a measure of problematic situations and coping strategies for chronically- ill school-age and adolescent children and their parents, 2) a three-wave longitudinal validation of the adolescent-parent measure of coping efficacy, 3) a diary study of sibling relationships, parental differential treatment, and social support, and 4) a diary study examining role strain in couples raising a chronically ill vs. healthy child. The theoretical framework guiding this research is the need for greater contextual specificity in the definitions and measurement of stress and coping processes. Studies funded by a FIRST Award apply a behavior-analytic model to identify both the specific tasks and situations that are problematic for children and adolescents with cystic fibrosis and the most effective coping efforts. In contrast, prior research has been limited by the use of global, poorly defined constructs. This research also seeks to advance theory by moving away from the study of individuals toward the evaluation of relationships within family systems; the extent of congruence among family members in perceptions of problems and use of coping strategies will be related to outcomes such as family conflict. An RCDA would greatly enhance my development as a researcher by enabeling me to obtain training in: 1) Dynamical systems theory and methods, 2) Intensive observational techniques, and 3) Development and evaluation of preventive interventions for chronically ill children and their families. The family system is a complex one and will require new models and data analytic techniques to represent its nonlinear pattern of interactions. Dr. Smith will advise me in the application of dynamical systems theory to the proposed diary methods. DR. Corsaro, an expert on qualitative data collection methods with children, will provide supervision in this area. The IU Diabetes Research and Training Center will instruct me in the design and implementation of interventions for adolescents and their families, and will assist in adapting my measures to their population. Additional training in intervention methods will be provided by Drs. La Greca and Sandler. This research should advance understanding of the effects of chronic stress on children and families, in addition to providing the basis for developing preventive behavioral interventions. Finally, an RCDA will enable me to obtain critical training experiences from an eminent group of researchers to facilitate my growth as a theorist and researcher.